Mapping Consumer Movement Across Supplement Retail Chains

👉 Check out the Observable notebook here: https://observablehq.com/d/bdf1429be57b0f08
It includes the full visualization stack and a breakdown of how I processed and cleaned the data to make it D3-Ready.

Overview

In today’s hyper-competitive retail landscape, knowing where your customers come from (and where they go next) can unlock powerful strategic advantages. For this sample project, I used 1 million+ rows of mobility data to understand competitive foot traffic behavior across top supplement retailers: Vitamin Shoppe, CVS, Walgreens, and GNC.

Rather than relying on surveys or static dashboards, this approach uses real-time, real-world location data to uncover how shoppers move between brands. Do people visit CVS before heading to Walgreens? Is GNC a common next stop after Vitamin Shoppe? These are the kinds of questions we set out to answer visually and intuitively.

I started by tracking individual device movement over time, assigning directionality to each visit based on whether a competing store was visited before or after a focal brand. From there, we transformed this raw location data into a series of visual layers:

• 🧭 A geo-time map showing the massive scale and density of the data (millions of device pings captured across North America).

• 🔁 An alluvial Sankey diagram showing how shoppers flow from one brand to another over time, revealing behavioral patterns like loyalty or brand switching.

• 📈 A Lift vs. Confidence chart using association rule mining to quantify which visitation patterns are statistically meaningful (not just popular).

Together, these views turn passive location data into actionable competitive intelligence.